[OpenJDK 2D-Dev] Provide access to data offset in WritableRaster in Java 9
philip.race at oracle.com
Thu Jul 13 19:32:47 UTC 2017
PS when filing the bug a self-contained (fully compilable) code example
showing what you would are trying to do will help.
Yes .. I guess you will need to use the internal API in that case but
it is a lot easier to unambigiously convey reqiurements with code if
On 07/13/2017 12:18 PM, Phil Race wrote:
> Yes this is the right list, and my reply on jigsaw-dev stands :-
> Sounds like you were accessing jdk internals and found that you
> mostly can do away with that except for sub-images.
> What you should really do is file an issue at bugs.java.com as
> client-libs/2d for cat/subcat.
> If this had been raised earlier in JDK 9 development - we could have
> looked into
> it in time. Now it will have to wait for a follow on release.
> On 7/13/2017 12:13 PM, Peter A wrote:
>> Apologies since this probably not the correct list, but I was
>> referenced here from another Java list. I've actually been getting
>> bounced around to a few mailing lists. I'm hopeful that this is the
>> right now!
>> The high level API in a BufferedImage is very very very slow. To get
>> around that problem, in previous versions of Java, the internal
>> rasters which were defined in sun.awt.image were accessed. Doing so
>> enabled real-time computer vision in Java.
>> Accessing the low level Rasters is no longer practical in Java 9.
>> After this problem was reported by one of my users I looked into it
>> and *almost* found a work around Unfortunately the higher level
>> WritableRaster does not provide access to the offset inside its
>> internal data array. This makes processing of subimages
>> impossible. My suspicion is that it is most likely an oversight
>> because it provides access to every other piece of information needed
>> and the raw data. It would be great if getDataOffset() could be
>> moved into WritableRaster or one of its parents instead of being
>> hidden in children of WritableRaster which are no longer accessible.
>> Just to clarify the raw arrays are stored inside of a DataBuffer and
>> that data structure contains an offset. This offset is always set to
>> zero and the offset inside of WritableRaster is what is needed, e.g.
>> - Peter
>> "Now, now my good man, this is no time for making enemies." —
>> Voltaire (1694-1778), on his deathbed in response to a priest asking
>> that he renounce Satan.
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